A man claiming to be the brother of Meriam Ibrahim, the Sudanese woman sentenced to death for apostasy, has said she deserves to die unless she repents of her “crime”.

Al Samani Al Hadi Mohamed Abdullah, who says he is one of three brothers, said the convicted woman’s real name is Abrar Al Hadi, but that she changed it after being fed “potions” by her husband.

In an interview with CNN he said: “She went missing in Ramadan [July] last year for 45 days. That's when we went to the police. When she was picked up we found her face was different, the way she looked at us was different. She was bewitched.

“When she stood in front of the court she said her name was Meriam Yahya [Ibrahim]. We were shocked.”

And he said that she should be “executed” unless she renounces her actions.

Last month a then heavily pregnant Ms Ibrahim was sentenced by a Khartoum court to 100 lashes and hanging after being convicted of apostasy and adultery for marrying a non-Muslim. Although she was raised as a Christian by her mother, Sudanese law states a child must follow their father’s religion and Ms Ibrahim’s marriage was deemed invalid on these grounds.

She gave birth to a baby girl in jail, where her 18-month-old son is also living with her. People all over the world have rallied together to condemn her treatment, with Amnesty International describing the sentence as “abhorrent,” and the US State Department saying it was “deeply disturbed”.

Mr Al Hadi alleged that Ms Ibrahim met her husband, Daniel Wani, following her graduation . He claimed that Mr Wani, whom he referred to as “the Priest”, converted his sister to Christianity using “potions”.

His account goes against that of the couple, who claim they were introduced by Mr Wani’s sister in 2009 and married in 2011. Mr Wani said he had never met his “brother-in-law” until the start of his wife’s trial.

On Wednesday, the lawyer for Ms Ibrahim announced that she has launched an appeal against her sentence.

The appeal demands the release of Meriam Ibrahim, saying the court that tried her committed “procedural errors,” Eman Abdul-Rahim told The Associated Press.

But Mr Al Hadi is unmoving in his judgement of his “sister”.

“It's one of two; if she repents and returns to our Islamic faith and to the embrace of our family then we are her family and she is ours. We are prepared to hold her dearer than the apples of our eyes,” he told CNN.

“But if she refuses she should be executed. Why would I indulge my humanity, my emotions and incur the wrath of my Lord? That's not how it works for us."